Adjustable drill depth guide

ABSTRACT

An adjustable drill depth guide includes a first sleeve, a second sleeve and a stop member. The first sleeve includes a longitudinal axis and defines a helical slot disposed about the longitudinal axis. The second sleeve is concentrically arranged relative to the first sleeve and is axially adjustable relative to the first sleeve for adjusting a length of the adjustable drill depth guide. The stop member extends radially from the second sleeve and is disposed in the helical slot. The stop member is selectively received at various positions along the helical slot to positively locate the second sleeve relative to the first sleeve in the axial direction.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/731,663, filed on Nov. 30, 2012. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present disclosure relates to an adjustable drill depth guide, andmore particularly to a device and method for adjusting the depth of adrill bit into a bone.

BACKGROUND

This section provides background information related to the presentdisclosure which is not necessarily prior art.

In general, the human musculoskeletal system is composed of a variety oftissues including bone, ligaments, cartilage, muscle, and tendons.Tissue damage or deformity stemming from trauma, pathologicaldegeneration, or congenital conditions often necessitates surgicalintervention to restore function. Surgical intervention can include anysurgical procedure that can restore function to the damaged tissue orcorrect the deformity, which can require the use of one or moreorthopedic prosthesis, such as orthopedic nails, screws, implants, etc.For example, in order to restore function to or correct a deformity ofthe spinal column, one or more implants can be coupled to each vertebralbody and interconnected via a suitable device. Implants or anchors canbe coupled to each vertebral body, and a connecting device, such as arod, can be coupled to each of the anchors to stabilize or fix thevertebral bodies relative to each other. Generally, multiple anchors orbone screws can be attached to each vertebral body so that multiple rodscan be used to stabilize the spinal column. Holes of various depths maybe drilled in the vertebral bodies to prepare the bone to receive thebone screws.

SUMMARY

This section provides a general summary of the disclosure, and is not acomprehensive disclosure of its full scope or all of its features.

The present teachings relate to an instrument for use in preparing abone to receive a bone screw. More specifically, the present teachingsrelate to a drill depth guide that can be quickly and easily adjusted toachieve a desired drill depth.

According to one particular aspect, the present disclosure provides anadjustable drill depth guide. The adjustable drill depth guide includesa first sleeve, a second sleeve, a third sleeve, and a biasing member.The first sleeve includes a longitudinal axis, a first proximal end, afirst distal end, a first longitudinal bore extending from the firstproximal end to the first distal end, a helical slot disposed about thelongitudinal axis, and a plurality of notches extending axially from thehelical slot. The second sleeve is at least partially disposed withinthe first longitudinal bore, and extends along the longitudinal axisfrom a second proximal end to a second distal end. The second sleeveincludes a second longitudinal bore and a radially extending stopmember. The radially extending stop member is selectively engageablewith at least one notch of the plurality of notches. The third sleeveincludes a third proximal end, a third distal end, and a thirdlongitudinal bore extending from the third proximal end to the thirddistal end. The third sleeve is concentrically disposed relative to thefirst sleeve. The biasing member is disposed substantially adjacent toan outer wall of the third sleeve and biases the second proximal end inthe direction of the third distal end.

According to another particular aspect, the present disclosure providesan adjustable drill depth guide. The adjustable drill depth guideincludes a first sleeve, a second sleeve, and stop member. The firstsleeve includes a longitudinal axis and defines a helical slot disposedabout the longitudinal axis. The second sleeve is concentricallyarranged relative to the first sleeve and is axially adjustable relativeto the first sleeve for adjusting a length of the adjustable drill depthguide. The stop member extends radially from the second sleeve and isdisposed in the helical slot. The stop member is selectively received atvarious positions along the helical slot to positively locate the secondsleeve relative to the first sleeve in the axial direction.

According to yet another particular aspect, the present disclosureprovides a method of adjusting the length of a drill depth guide. Themethod includes providing an adjustable drill depth guide that includesa first sleeve having a helical slot, a second sleeve at least partiallydisposed within the first sleeve, a radially extending stop membercoupled to the third sleeve and operably disposed within the helicalslot, and a biasing member biasing a distal end of the second sleeve ina first axial direction. The method also includes moving the radiallyextending stop member in a second axial direction opposite the firstaxial direction. The method further includes rotating the second sleeverelative to the first sleeve to move the radially extending stop memberin at least one of the first axial direction and the second axialdirection.

Further areas of applicability will become apparent from the descriptionprovided herein. The description and specific examples in this summaryare intended for purposes of illustration only and are not intended tolimit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present disclosure.

FIG. 1 is a perspective view of an adjustable drill depth guideconstructed in accordance with the teachings of the present disclosure.

FIG. 2 is a front view of the adjustable drill depth guide of FIG. 1.

FIG. 3 is a rear view of the adjustable drill depth guide of FIG. 1.

FIG. 4 is a bottom view of the adjustable drill depth guide of FIG. 1.

FIG. 5 is a front view of the adjustable drill depth guide of FIG. 1.

FIG. 6 is a side view of the adjustable drill depth guide of FIG. 1.

FIG. 7 is another side view of the adjustable drill depth guide of FIG.1.

FIG. 8 is a cross sectional view of the of the adjustable drill depthguide of FIG. 1 taken along line 8-8 of FIG. 2.

FIG. 8A is a close-up view of area 8A of FIG. 8.

FIG. 9 is an exploded view of the adjustable drill depth guide of FIG.1.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference tothe accompanying drawings.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

The terminology used herein is for the purpose of describing particularexample embodiments only and is not intended to be limiting. As usedherein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. The terms “comprises,” “comprising,” “including,” and“having,” are inclusive and therefore specify the presence of statedfeatures, integers, steps, operations, elements, and/or components, butdo not preclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof. The method steps, processes, and operations described hereinare not to be construed as necessarily requiring their performance inthe particular order discussed or illustrated, unless specificallyidentified as an order of performance. It is also to be understood thatadditional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,”“connected to,” or “coupled to” another element or layer, it may bedirectly on, engaged, connected or coupled to the other element orlayer, or intervening elements or layers may be present. In contrast,when an element is referred to as being “directly on,” “directly engagedto,” “directly connected to,” or “directly coupled to” another elementor layer, there may be no intervening elements or layers present. Otherwords used to describe the relationship between elements should beinterpreted in a like fashion (e.g., “between” versus “directlybetween,” “adjacent” versus “directly adjacent,” etc.). As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items.

Although the terms first, second, third, etc. may be used herein todescribe various elements, components, regions, layers and/or sections,these elements, components, regions, layers and/or sections should notbe limited by these terms. These terms may be only used to distinguishone element, component, region, layer or section from another region,layer or section. Terms such as “first,” “second,” and other numericalterms when used herein do not imply a sequence or order unless clearlyindicated by the context. Thus, a first element, component, region,layer or section discussed below could be termed a second element,component, region, layer or section without departing from the teachingsof the example embodiments.

Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. Spatiallyrelative terms may be intended to encompass different orientations ofthe device in use or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.Thus, the example term “below” can encompass both an orientation ofabove and below. The device may be otherwise oriented (rotated 90degrees or at other orientations) and the spatially relative descriptorsused herein interpreted accordingly.

With reference to FIGS. 1-9, an adjustable drill depth guide assemblyconstructed in accordance with the present teachings is illustrated andidentified at reference character 10. The adjustable drill depth guideassembly 10 may be used to control the depth by which a tap or drill bit12 penetrates a bone 14. According to one exemplary use, the adjustabledrill depth guide assembly 10 may be particularly adapted for use inspinal fixation procedures. It will also be appreciated, however, thatthe present teachings may be adapted to control the penetration depth ofa drill bit into any type of material or component.

The adjustable drill depth guide assembly 10 may generally include a tipor end sleeve 16, a control sleeve 18, an adjustment sleeve 20, a collar22, an inner sleeve 24, a biasing member 26, and a handle assembly 28.As illustrated, the end sleeve 16, the control sleeve 18, the adjustmentsleeve 20, the collar 22, and the inner sleeve 24 may together define aguide barrel 25 having a longitudinal axis 30 that accepts the drill bit12.

As illustrated in FIGS. 8 and 8A, the end sleeve 16 may extend between aproximal end 32 and a distal end 34 along the longitudinal axis 30, andmay include a bore 36, and a counterbore 38. The bore 36 may extendbetween the proximal end 32 and the distal end 34 of the end sleeve 16.The counterbore 38 may extend longitudinally from the proximal end 32.As illustrated, an annular surface 42 extending between and connectingthe bore 36 and the counterbore 38 may be tapered or chamfered togenerally guide the drill bit 12 along the longitudinal axis 30 and inthe direction of the bone 14.

The proximal end 32 of the end sleeve 16 may include an externallythreaded portion 44. The distal end 34 of the end sleeve 34 may includea toothed portion 46 having a plurality of axially extending teeth. Thetoothed portion 46 may help to secure the placement of the adjustabledrill depth guide assembly 10 relative to the bone 14 or other workingsurface. An outer surface 47 of the end sleeve 16 may include a knurledportion 48 to allow a user to better grip and maneuver the adjustabledrill depth guide assembly 10.

The control sleeve 18 may extend between a proximal end 50 and a distalend 52 along the longitudinal axis 30. The control sleeve 18 may includea generally cylindrical neck portion 54 and a generally cylindrical bodyportion 56. The body portion 56 may extend longitudinally from theproximal end 50 of the control sleeve 18 to a distal end 55 of the bodyportion 56. The neck portion 54 may be integrally and concentricallyformed with the body portion 56 and may extend longitudinally from thedistal end 55 of the body portion 56 to the distal end 52 of the controlsleeve 18. The neck portion 54 may have a smaller diameter than the bodyportion 56 and may include an annular groove 57. The annular groove 57may support a retaining ring 59. In an assembled configuration, the neckportion 54 may be concentrically and rotatably disposed within thecounterbore 38 of the end sleeve 16.

A bore 58 may extend longitudinally from the proximal end 50 to thedistal end 52 of the control sleeve 18. A counterbore 60 may extendlongitudinally from the proximal end 50 to a location between theproximal end 50 and the distal end 52 of the control sleeve 18. Anannular surface 62 may extend between and connect the bore 58 and thecounterbore 60. As will be explained in more detail below, the annularsurface 62 may be tapered or chamfered and may prevent axialdisplacement of the adjustment sleeve 20 relative to the control sleeve18 in an assembled configuration.

The body portion 56 of the control sleeve 18 may include an aperture 64and a helical slot 66. The aperture 64 may extend laterally through thesidewall of the control sleeve 18 to allow a user to view the innersleeve 24 within the bore 58. It will be appreciated that the helicalslot 66 may extend around the periphery of the control sleeve 18 anynumber of revolutions, or fractions thereof, within the scope of thepresent teachings. In one configuration, the helical slot 66 extendsapproximately seven hundred twenty degrees around the control sleeve 18.The helical slot 66 may include a plurality of axially extending notches70. The notches 70 may extend axially in the direction of the distal end52 of the control sleeve 18, such that the lower edge (relative to theview in FIG. 1, for example) of the helical slot 66 has a generallyscalloped or waved configuration. In one configuration, the axialdistance between adjacent notches 70 may be approximately 2 millimeters.

The adjustment sleeve 20 may extend between a proximal end 72 and adistal end 74 along the longitudinal axis 30. The proximal end 72 of theadjustment sleeve 20 and the distal end 34 of the end sleeve 16 maygenerally define a length of the drill depth guide 10 along thelongitudinal axis 30, and thus the distance by which the drill bit 12extends beyond the distal end 34 of the end sleeve 16. The adjustmentsleeve 20 may include a generally cylindrical head portion 76 and agenerally cylindrical stem portion 78. The head portion 76 may have alarger diameter than the stem portion 78. A generally frustoconicalintermediate portion 80 may extend between and connect the head portion76 and the stem portion 78. While the adjustment sleeve 20 is describedherein as including a generally cylindrical head portion 76, a generallycylindrical stem portion 78, and generally frustoconical intermediateportion 80 therebetween, it will be appreciated that the head portion76, the stem portion 78 and the intermediate portion may have othergeometries within the scope of the present teachings. The head portion76 may be integrally formed with the stem portion 78 and theintermediate portion 80 as a monolithic construct.

The adjustment sleeve 20 may further include a bore 84 and a aperture88. The bore 84 may extend longitudinally from the proximal end 72 tothe distal end 74 of the adjustment sleeve 20. The aperture 88 mayextend laterally through the sidewall of the stem portion 78 of theadjustment sleeve 20.

In an assembled configuration, the stem portion 78 of the adjustmentsleeve 20 may be concentrically and rotatably disposed with the bore 58of the control sleeve 18. A radially extending stop member, such as apin 90, may extend through the helical slot 66 and into engagement withthe aperture 88. In one configuration, the aperture 88 may be internallythreaded and the pin 90 may include an externally threaded portion 91,such that rotating the pin 90 with a screwdriver (not shown) or othersuitable tool will threadably engage the pin 90 with the aperture 88. Inother configurations, the pin 90 may be secured within the aperture 88by utilizing a press-fit engagement, an adhesive, or other suitabletechnique. In one configuration, the pin 90 is permanently coupledwithin the aperture 88 using a press-fit engagement.

The collar 22 may extend between a proximal end 92 and a distal end 94along the longitudinal axis 30. While the collar 22 is generallyillustrated as a cylindrical member, it will be appreciated that thecollar 22 may have other geometries within the scope of the presentteachings. The collar 22 may include a bore 96 and a counterbore 98. Thebore 96 may extend longitudinally through the collar 22 from theproximal end 92 to the distal end 94. The counterbore 98 may extendlongitudinally from the distal end 94 to a location between the proximalend 92 and the distal end 94 of the control sleeve 18, and may includean internally threaded portion 100.

In the assembled configuration, the collar 22 may be concentricallydisposed around the end sleeve 16 and the control sleeve 18. Asillustrated, the threaded portion 100 of the collar 22 may engage thethreaded portion 44 of the end sleeve 16, so that the end sleeve 16 canbe removed from the collar 22 for cleaning or otherwise servicing theassembly 10. The neck portion 54 of the control sleeve 18 may beconcentrically disposed within the collar 22 such that the bore 96 abutsthe neck portion 54 of the control sleeve 18, and the proximal end 92 ofthe collar 22 abuts the end 55 body portion 56 of the control sleeve 18.

The guide assembly 10 may further include at least one washer 108. Inone configuration, the guide assembly includes two washers 108. Asillustrated, in the assembled configuration, the washers 108 may beaxially disposed between the counterbore 98 of the collar 22 and theproximal end 32 of the end sleeve 16. The neck portion 54 of the controlsleeve 18 may be concentrically disposed within the washers 108, suchthat the retaining ring 59 engages the axial end of the washers 108 andthe distal end of the neck portion 54 to prevent axial displacement ofthe control sleeve 18 relative to the collar 22 and to allow theretaining ring 59 and the control sleeve 18 to rotate relative to theend sleeve 16.

The inner sleeve 24 may extend between a proximal end 112 and a distalend 114 along the longitudinal axis 30. The inner sleeve 24 may be agenerally cylindrical member having a bore 116 extending longitudinallytherethrough from the proximal end 112 to the distal end 114. Theproximal end 112 of the inner sleeve 24 may include a generallycylindrical neck portion 118 defining an axial stop surface 120. Thestop surface 120 may be disposed between the proximal end 112 and thedistal end 114 of the inner sleeve 24. The neck portion 118 may includea laterally extending aperture 122. The distal end 114 of the innersleeve 24 may include a radially extending flange or lip 124 defining anaxial stop surface 126.

In the assembled configuration the inner sleeve 24 may be concentricallydisposed within the end sleeve 16, the control sleeve 18, the adjustmentsleeve 20, and the collar 22. The neck portion 118 of the inner sleeve24 may be disposed within the adjustment sleeve 20 such that the distalend 74 of the adjustment sleeve 20 is disposed adjacent to the stopsurface 120 of the inner sleeve 24. The inner sleeve 24 may be fixed foraxial displacement with the adjustment sleeve 20. Specifically, in oneconfiguration the pin 90 may extend through the adjustment sleeve 20 andat least partially within the aperture 122 of the inner sleeve 24.

In one configuration, the inner sleeve 24 may include a metering portion(the portion of inner sleeve 24 visible through aperture 62) showingdistances such as inches, millimeters, centimeters, etc. The meteringportion of the inner sleeve 24 may be visible through the aperture 64 ofthe control sleeve 18, such that the user can determine the distance bywhich the drill bit 12 will extend beyond the distal end 34 of the endsleeve 16.

The biasing member 26 may be disposed between the control sleeve 18 andthe inner sleeve 24. In one configuration, the biasing member 26 may bea helical compression spring longitudinally extending between a proximalend 128 and a distal end 130. The biasing member 26 may beconcentrically disposed around the inner sleeve 24, and concentricallydisposed within the counterbore 38 of the end sleeve 16. The proximalend 128 of the biasing member 26 may be disposed adjacent the distal end52 of the control sleeve 18. The distal end 130 of the biasing member 26may be disposed adjacent the stop surface 126 of the inner sleeve 24.Accordingly, in the assembled configuration, the biasing member 26 maybe operable to bias the inner sleeve 24 and the adjustment sleeve 20relative to the control sleeve 18. Specifically, the biasing member 26may be operable to bias the distal end 114 of the inner sleeve 24 awayfrom the distal end 52 of the control sleeve 18, and bias the proximalend 72 of the adjustment sleeve 20 in the direction of the distal end 34of the end sleeve 16. Accordingly, the biasing member 26 may be operableto bias the pin 90 into engagement with at least one of the notches 70of the helical slot 66.

The handle assembly 28 may include a collar 132, a shaft 134, a handle136, and a cap 138. The collar 132 may define a longitudinally extendingbore 140 and an aperture 142. In an assembled configuration, the controlsleeve 18 may be concentrically disposed within the bore 140, such thatthe handle assembly 28 can be rotated or otherwise maneuveredindependently of the end sleeve 16.

The shaft 134 may extend in a generally arcuate configuration from aproximal end 144 to a distal end 146. In one configuration, the shaft134 may be constructed from aluminum to improve the weight and strengthcharacteristics of the shaft 134. It will also be appreciated that theshaft 134 may be constructed from any other similarly suited material.The proximal end 144 of the shaft 134 may include an externally threadedportion 145. The distal end 146 of the shaft 134 may be mounted to thecollar 132, and may include an aperture 147. In one configuration, theaperture 147 of the shaft 134 may be aligned with the aperture 142 ofthe collar. A pin may be disposed within the aperture 147 and theaperture 142 to secure the shaft 134 to the collar 132. It will also beappreciated that the shaft 134 may be mounted to the collar 132 usingother methods and configurations within the scope of the presentteachings.

The handle 136 may extend from a proximal end 150 to a distal end 152.In one configuration, the handle 136 is formed from silicone to allow auser to better grip the handle 136. It will also be appreciated that thehandle 136 may be formed from any other similarly suited material. Theproximal end 150 of the handle 136 may include a first internallythreaded portion 154. The distal end 152 of the handle 136 may include asecond internally threaded portion 156. The proximal end 144 of theshaft 134 may be mounted to the handle 136 such that the threadedportion 145 of the shaft 134 is threadably engaged with the secondthreaded portion 156 of the handle 136. It will also be appreciated thatthe handle 136 may be mounted to the shaft 134 using a press-fitengagement, adhesive, or any other suitable technique.

The cap 138 may include a head portion 158 and a stem portion 160. Thestem portion 160 may be externally threaded, such that the cap 138 canbe mounted to the handle 136 by threadably engaging the stem portion 160with the threaded portion 154 of the handle.

To adjust the depth by which a drill bit 12 extends beyond the distalend 34 of the end sleeve 16, the user may apply an axial force F1 to theadjustment sleeve 20 to overcome a compressive biasing force F2 of thebiasing member 26, as illustrated in FIGS. 8 and 8A. The force F1 maycause the proximal end 72 of the control sleeve 72 to travel away fromthe distal end 34 of the end sleeve 16, and cause the pin 90 todisengage the notch 70, such that the pin 90 is disposed within thehelical slot 66 of the control sleeve 18. The user may then rotate theadjustment sleeve 20 about the longitudinal axis 30 relative to thecontrol sleeve 18, such that the pin 90 traverses the helical slot 66,and the proximal end 72 of the adjustment sleeve 20 travels in the axialdirection relative to the distal end 34 of the end sleeve 16. To securethe depth by which a drill bit 12 extends beyond the distal end 34 ofthe end sleeve 16, the user may release the axial force F1, such thatthe biasing force F2 causes the pin 90 to travel in the axial directionand into engagement with one of the notches 70, thus preventing theadjustment sleeve 20 from rotating relative to the control sleeve 18.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

What is claimed is:
 1. A method of adjusting a length of a drill depthguide, the method comprising: providing an adjustable drill depth guidecomprising: a first sleeve having a helical slot; a second sleeve atleast partially disposed within the first sleeve, the second sleevehaving a proximal end; a radially extending stop member coupled to thesecond sleeve and operably disposed within the helical slot; asurface-contacting sleeve rotatably coupled to the first sleeve andaxially locked with the first sleeve, the surface-contacting sleevehaving a distal end; and a biasing member biasing the second sleeve in afirst axial direction of the surface-contacting sleeve, wherein thebiasing member biases the second sleeve in the first axial directiontoward the distal end of the surface-contacting sleeve; moving theradially extending stop member in a second axial direction opposite thefirst axial direction; and rotating the second sleeve relative to thefirst sleeve to move the radially extending stop member in a least oneof the first axial direction and the second axial direction to change adistance between the proximal end and the distal end.
 2. The method ofclaim 1, wherein moving the radially extending stop member furthercomprises axially moving the second sleeve within the surface-contactingsleeve.
 3. The method of claim 2, wherein the second sleeve includes aninner sleeve coupled to the second sleeve within the first sleeve, theinner sleeve extending into the surface-contacting sleeve.
 4. The methodof claim 1, further comprising rotating the first sleeve relative to thesurface-contacting sleeve independently of the axial location of thesecond sleeve.
 5. The method of claim 4, wherein rotating the firstsleeve relative to the surface-contacting sleeve further comprisesrotating the first sleeve relative to the surface-contacting sleevewhile the surface-contacting sleeve is engaged with a surface.
 6. Themethod of claim 5, further comprising pushing the distal end of thesurface-contacting sleeve into engagement with the surface via pushingthe first sleeve axially against the surface-contacting sleeve via aretaining ring.
 7. The method of claim 6, further comprising rotatingand pushing the first sleeve relative to the surface-contacting sleeveusing a handle connected to the first sleeve.
 8. The method of claim 1,wherein rotating the second sleeve relative to the first sleevecomprises rotating the second sleeve relative to the first sleeveindependently of the first sleeve rotating relative to thesurface-contacting sleeve.
 9. The method of claim 1, further comprisingsimultaneously rotating the second sleeve and the first sleeve relativeto the surface-contacting sleeve.
 10. The method of claim 1, whereinmoving the radially extending stop member further comprises moving thesecond sleeve within the first sleeve to show distances located on ametering portion of the second sleeve in an aperture located on thefirst sleeve.
 11. The method of claim 1, wherein moving the radiallyextending stop member further comprises engaging the radially extendingstop member with a notch on the helical slot to limit biasing of thebiasing member.
 12. A method of adjusting an adjustable drill depthguide, the method comprising: engaging a distal end of asurface-contacting sleeve with a surface, the surface-engaging sleevedefining a drill axis; moving a handle connected to a control sleeve torotate the control sleeve relative to the surface-contacting sleeve andto position the drill axis; and adjusting an axial position of anadjustment sleeve relative to the control sleeve to define an overalllength of the adjustable drill depth guide along the drill axis.
 13. Themethod of claim 12, wherein moving the handle connected to the controlsleeve comprises rotating the control sleeve against a retaining ringcoupling the control sleeve to the surface-contacting sleeve.
 14. Themethod of claim 13, wherein rotating the control sleeve against theretaining ring further comprises inhibiting axial movement between thecontrol sleeve and the surface-contacting sleeve.
 15. The method ofclaim 12, wherein adjusting the axial position of the adjustment sleeverelative to the control sleeve comprises: overcoming a spring force of abiasing mechanism; and moving a radially extending stop member in a sloton the control sleeve.
 16. The method of claim 15, wherein adjusting theaxial position of the adjustment sleeve relative to the control sleevefurther comprises aligning depth indicia on the adjustment sleeve with awindow on the control sleeve.
 17. The method of claim 12, furthercomprising attaching an inner sleeve to the adjustment sleeve forsliding within the surface-contacting sleeve.
 18. A method of adjustinga length of a drill depth guide, the method comprising: engaging adistal end of a surface-contacting sleeve with a surface; positioning acontrol sleeve connected to the surface-contacting sleeve; adjusting anaxial position of an adjustment sleeve relative to the control sleeve todefine an overall length of the adjustable drill depth guide along thedrill axis; viewing a metering portion of the adjustment sleeve throughan aperture in the control sleeve to provide a showing of a drilldistance of a drill bit beyond the distal end of surface-contactingsleeve; and simultaneously rotating the control sleeve and theadjustment sleeve relative to the surface-contacting sleeve.
 19. Themethod of claim 18, further comprising inserting a drill bit into thedrill depth guide such that a length of the drill bit extending from thesurface-contacting sleeve equals a depth indicated by the depth indicia.